Genome-wide investigation of DNA methylation marks associated with FV Leiden mutation

Poly (ADP-ribose) Polymerase-1 modulations in the genesis of thrombosis

Thrombosis, a coagulation disorder, occurs due to altered levels of coagulation, fibrinolytic and immune factors, which are otherwise known to maintain hemostasis in normal physiological conditions. Here, we review the direct and indirect participation of a multifunctional nuclear enzyme poly (ADP-ribose) polymerase-1 (PARP1) in the expression of key genes and cellular processes involved in thrombotic pathogenesis. PARP1 biological activities range from maintenance of genomic integrity, chromatin remodeling, base excision DNA repair, stress responses to cell death, angiogenesis and cell cycle pathways. However, under homeostatic imbalances, PARP1 activities are linked with the pathogenesis of diseases, including cancer, aging, neurological disorders, and cardiovascular diseases. Disease-associated distressed cells employ a variety of PARP-1 functions such as oxidative damage exacerbations, cellular energetics and apoptosis pathways, regulation of inflammatory mediators, promotion of endothelial dysfunction, and ERK-mediated signaling in pathogenesis. Thrombosis is one such pathogenesis that comprises exacerbation of coagulation cascade due to biochemical alterations in endothelial cells, platelet activation, overexpression of adhesion molecules, cytokines release, and leukocyte adherence. Thus, the activation of endothelial and inflammatory cells in thrombosis implicates a potential role of PARP1 activation in thrombogenesis. This review article explores the direct impact of PARP1 activation in the etiology of thrombosis and discusses PARP1-mediated endothelial dysfunction, inflammation, and epigenetic regulations in the disease manifestation. Understanding PARP1 functions associated with thrombosis may elucidate novel pathogenetic mechanisms and help in better disease management through newer therapeutic interventions targeting PARP1 activity.

Venous thromboembolism in hospital emergency room. A retrospective study on climatic effect

Several cardiovascular conditions exhibit seasonality in frequency and mortality, but little is known about the seasonality of Venous ThromboEmbolism (VTE), a very relevant medical condition, and seasonal influences are still conflicting. Patients having co-morbidities, individual suffered from dyspnea, swelling, edema of lower limb, pain (chest, lower limbs) are admitted frequently to the hospital emergency room (HER), particularly. Both mark a potential risk for VTE, that can be increased also by seasonality. A four years retrospective analysis (2016-2019) was carried out in individuals and patients admitted to the HER of the Hospital of Catania (a Mediterranean city of Sicily, Italy) to evaluate the VTE frequency and its seasonal differences, common symptoms, potential usage of some common laboratory tests. Dyspnea, swelling, edema of lower limb and pain (chest, lower limbs) were considered to suspect pulmonary embolism (PE) or for deep vein thrombosis of lower limb (DVT). Platelet count, platelet volume, fibrinogen, C-reactive protein, and D-dimer were considered. VTE frequency per year was 2.9/10,000 (2016), 4.9/10,000 (2017) 3.6/10,000 (2018), and 5.1/10,000 (2019) respectively. Dyspnea was highly frequent for PE, edema and lower limb pain were frequent in DVT patients. Fibrinogen, C reactive protein, and D-dimer values were found raised in all the VTE patients. Platelet volume was found higher in DVT than PE VTE events that occurred in warm periods were modestly greater (57 VTE: 38 DVT, 19 PE) compared to cold months (52 VTE: 34 DVT, 18 PE). Our results could be explained by the increased sweating due to the high temperatures, which in turn, can affect both on plasma concentration and on hematocrit value coupled to the reduction in atmospheric pressure determining both a hyper-coagulative condition. Climate seasonal characteristics, and environmental conditions in Catania city (Sicily) may be as reasonable items in expecting on different VTE rates in warm period compared to cold. This study highlights no specific symptoms, and confirms the common lab tests for individuals and patients admitted to HER as simple and helpful tools in initiating none or mini-invasive diagnostic strategy for the VTE. Finally, the climate/seasonality coupled with latitude can have a direct influence on the incidence of DVT.

Blood triglyceride levels are associated with DNA methylation at the serine metabolism gene PHGDH

Efficient interventions to reduce blood triglycerides are few; newer and more tolerable intervention targets are needed. Understanding the molecular mechanisms underlying blood triglyceride levels variation is key to identifying new therapies. To explore the role of epigenetic mechanisms on triglyceride levels, a blood methylome scan was conducted in 199 individuals from 5 French-Canadian families ascertained on venous thromboembolism, and findings were replicated in 324 French unrelated patients with venous thromboembolism. Genetic context and functional relevance were investigated. Two DNA methylation sites associated with triglyceride levels were identified. The first one, located in the ABCG1 gene, was recently reported, whereas the second one, located in the promoter of the PHGDH gene, is novel. The PHGDH methylation site, cg14476101, was found to be associated with variation in triglyceride levels in a threshold manner: cg14476101 was inversely associated with triglyceride levels only when triglyceride levels were above 1.12 mmol/L (discovery P-value = 8.4 × 10-6; replication P-value = 0.0091). Public databases findings supported a functional role of cg14476101 on PHGDH expression. PHGDH catalyses the first step in the serine biosynthesis pathway. These findings highlight the role of epigenetic regulation of the PHGDH gene in triglyceride metabolism, providing novel insights on putative intervention targets.

SERPINC1 gene mutations in antithrombin deficiency

Existing evidence suggests that in most cases antithrombin deficiency can be explained by mutations in its gene, SERPINC1. We investigated the molecular background of antithrombin deficiency in a single centre family cohort study. We included a total of 21 families comprising 15 original probands and sixty-six relatives, 6 of who were surrogate probands for the genetic analysis. Antithrombin activity and antigen levels were measured. The heparin-antithrombin binding ratio assay was used to distinguish between the different subtypes of type II antithrombin deficiency. SERPINC1 mutations were detected by direct sequencing of all 7 exons and regulatory regions, and multiplex ligation-dependent probe amplification. Eighty-six per cent of the families had a detrimental SERPINC1 gene mutation that segregated in the family. We detected 13 different SERPINC1 gene mutations of which 5 were novel. Among all these mutations, 44% was associated with type I deficiency, whereas the remainder was associated with type II heparin binding site (11%), type II pleiotropic effect (33%), type II reactive site (6%) or had the antithrombin Cambridge II mutation (6%). The current study reports several novel SERPINC1 mutations, thereby adding to our knowledge of the molecular background of antithrombin deficiency. Finally, our results point out the importance of future research outside the conventional SERPINC1 gene approach.

Beta cell function and clinical course in three siblings with thiamine-responsive megaloblastic anemia (TRMA) treated with thiamine supplementation

Three siblings with thiamine-responsive megaloblastic anemia (TRMA) with a homozygous c.454delGGCATinsAT mutation in SLC19A2 are described. The index case presented at 14 months' old with severe non-ketotic hyperglycemia, dehydration, seizures and sinovenous thrombosis. She was started on insulin and developed sensorineural hearing loss around 2 years old. Two siblings were found to have the same mutation and were started on thiamine. One sibling developed transient hyperglycemia after several years of thiamine supplementation of 12 mg/kg that resolved with an increased thiamine dose (23 mg/kg). A younger sibling continues to remain diabetes-free on thiamine (24 mg/kg). The clinical course in this family suggests that there is an effect of thiamine on pancreatic beta cell function in patients with TRMA given the resolution of impaired fasting glucose with increasing thiamine dose in one sibling and the lack of diabetes to date in the siblings that were treated early with thiamine.